Japan's ruling party suffered a historic defeat Sunday. For the first time since the conservative Liberal Democratic Party (LDP) was formed in 1955, an opposition party has become the largest party in the upper house.

The powerful message delivered by Japanese voters has significant implications not only for Japan but also for the rest of the world, not least for its close ally, the United States.

The election result revives momentum in Japan toward creation of a viable two-party system, potentially ending the conservative postwar monopoly on power. Japanese voters expressed deep anxiety about the impact of economic change upon their treasured social order. They embraced the campaign of the Democratic Party (the main opposition) against growing income inequality and the failure of the state to take care of an aging population.

Equally important, the vote was a humiliating defeat for Prime Minister Shinzo Abe's agenda of giving priority to revising Japan's antiwar Constitution and allowing its military to take on a global role in support of the US. Democratic Party leader Ichiro Ozawa effectively portrayed Mr. Abe as a man out of touch with the concerns of ordinary Japanese. But he also articulated an alternative vision of Japan's international role, calling for closer ties to its Asian neighbors and sending troops overseas only under the auspices of United Nations peacekeeping missions.

Since 9/11, Japan has been among the most loyal, if not unquestioning, of US allies. It sent troops to Iraq, provided logistical support to the war in Afghanistan, and outdid the US in putting pressure on North Korea. Most recently, Abe echoed the rhetoric of the Bush administration, calling for formation of a "values-based" alliance of democracies along with India and Australia, implicitly aimed at containing a rising China. The election results will certainly slow, if not reverse, this tight synchronization.

For the business community, the vote will raise concerns that needed economic policy actions such as fiscal reforms will get stalled in a gridlocked parliament. The vote reminds politicians that the economic recovery has left an awful lot of Japanese behind, with real wages falling, youth unemployment high, and the elderly drawing down their savings to survive. Abe's feel-good rhetoric and focus on security just angered those Japanese.

There remains strong support for gradual change. Most Japanese want the country to take on a more "normal" security role, but one that will stop far short of overdrawn fears of a remilitarized Japan. And many Japanese, particularly in the younger generation, back economic reform, though not at the expense of social stability.

The most intriguing question is the future of Japan's democracy. Abe is resisting calls for his resignation, attributing the vote to a series of scandals in his Cabinet and most of all to the revelation that the government's national pension system had lost the records of some 50 million people. The election result was bad luck, Abe claimed, not a repudiation of his administration's overall policies -- a view shared by Washington policymakers.

Exit polls do confirm that voters were strongly motivated by these issues. But they also express little faith in the personal leadership of Abe, who tried to cover up the pension debacle. He suffered from an unfavorable comparison to his predecessor, Junichiro Koizumi, one of Japan's most popular postwar leaders.

But the election suggests that Mr. Koizumi's personal charisma only temporarily reversed a longer trend of drift away from the ruling conservatives, particularly by unaffiliated swing voters in Japan's cities and suburbs. Mr. Ozawa, one of Japan's most brilliant politicians, managed to both regain those voters and steal away traditional conservative backers in rural areas among farmers and pensioners worried about their future.

Ozawa, whom I have known for more than two decades, is a man of uncommon political vision. He is a former LDP stalwart who has relentlessly pursued the goal of creating a clearly defined two-party system that can create real competition. He was the architect of a split in the LDP that briefly brought the opposition to power in the early 1990s.

Over dinner last fall, Ozawa laid out to me what seemed then like an incredibly audacious plan to regain power. First to win a series of local elections, leading up to a defeat of the LDP in the upper house election, forcing in turn the dissolution of the lower house and new elections. He clearly hopes to split the LDP again and pry away its coalition partner, the New Komeito Party, as part of his strategy of realignment.

The Democratic Party has yet to demonstrate its own ability to rule, but it would be unwise to underestimate Ozawa. And it would be foolish to dismiss the desire for change delivered by Japanese voters on Sunday.

Reprinted with permission by the Christian Science Monitor.